Indestructible release mechanism for blasting cartridges



July 5, 1938. F. H. ARMSTRONG INDESTRUCTIBLE RELEASE MECHANISM FOR BLASTING CARTRIDGES Filed April 27, 1936 w VQ I; 2&5 Q3 w Patented- July 5, 1938 UNITED STATES PATENT OFFICE.

INDESTRUCTIBLE RELEASE MECHANISM FOR BLASTING CARTRIDGES Frank H. Armstrong, Chicago, 111., assignor to Cardox Corporation, a corporation of Illinois This invention relates to new and useful improvements in indestructible release mechanism for blasting cartridges. 7

The primary object of this invention is to provide mechanism for releasing blasting charges from indestructible cartridges or shells and wherein the release mechanism is of an inde-, structible character and is susceptible of being adjusted to release charges at different work performing pressures.

A furtherimportant object of the invention is to provide indestructible release mechanism for blasting cartridges which is completely embodied in a discharge cap adapted to'be detachably associated with a cartridge or shell.

A still further important object of the inven-. tion is to provide indestructible release mechanism which will operate to effect discharge of a blasting medium from a cartridge or shell and wherein the blasting medium may take the form of carbon dioxide gas generated by intensely heating liquid carbon dioxide or highly compressed air.

Anothe -object; of th invention is to provide indestructible release mechanism which operates automatically to effect discharge of a blasting medium from a cartridge or shell when the pressure of said blasting medium reaches a predetermined value within the shell and wherein the discharge mechanism is operated entirely by the pressure of the blasting charge within the cartridge or shell.

Other objects and advantages of the invention will be apparent during the course of the following description.

invention,

" line 3-: or

- In the accompanying drawing forming a part of' this specification and in which like numerals are employed todesignate like parts throughout the same,

Figure 1 is a longitudinal sectional view of the indestructible release mechanism embodying this Figure 2 is a transverse line 2-2 of'Figure 1, and

Figure 3 is a transverse sectional view taken on Fi ure-1. v In the drawing, wherein for the purpose of illustration is shown a preferred embodiment of f thisinvention, the reference character 10 designatesan indestructible cartridge or shell which is intended to receive a blasting charge that is to be released at a desired work performing pressure into the material to be broken down. The blasting charge may take the form of liquid carbon dioxide which is to be intensely heated by a chemical heater unit, or the like for converting the .liquid carbon dioxide into gas at a relatively high pressure. mechanism of a cartridge charged with carbon dioxide, reference may be had to the patent issectional view taken on For a complete understanding of the sued to Dent Ferrell et 9.1., 1,805,541, on May 19,

93 The blasting charge within the cartridge l0 also may take the form of air, or other gas compressed at a pressure less than the desired final blasting pressure at which the charge is to be released. The final blasting pressure may be obtained by intensely heating the initially compressed gas charge with either a chemical heater unit or a permanent electric resistance unit. Cartridges receiving chargeslof the above two desi nated characters are known in thetrade as precharged cartridges. The trade also is' familiar with what is termed post-charged cartridges. Cartridges of this character. are charged after they areplaced in a blastor drill hole. The charge usually takes the form or a compressed gas, such as air, whichis delivered to the cartridge from a portable compressor unit orfrom a portable storage tankf'o'r receiver, unit. It will be understood, as the description of the release mechanism embodying, this invention proceeds that the said mechanism will operate. very efiectlvely to release'fthe charge from a post-charged cartridge whemair, or other gases, is compressed in the cartridge l0 to the pressure at which the release mechanism is set to operate.

Figure 1 illustrates the discharge end of the,

cartridge 1'0? This end is provided with an internally threaded terminal portion ll. Spaced'ax-' ially inwardly of this threaded portion is a shoul-' portion Id of a tubular discharge cap. [5. Spaced provided with a series of obliquely arranged dis?" charge ports iii. A shoulder I1 is formed i'n'the bore offthe discharge cap 15 by the formation of an enlarged cylinder or chamber portion I8 within the cap bore.

I Threadedly connected tovthe outer end of the discharge cap I5 is a closureplug l 9. Apacking.

ring or gasket 20 is arranged between the closure plug I9 and an adjacent surface of the cap [5 to prevent leakage between these two elements. Threadedly mounted in a pocket 2 l formed in the plug I9 is a valve member 22 which may be backed off to permit fluid trapped in the cylinder 18 to be discharged through the port 23, formed in the plug l9. The utility of this valve 22 will befully explained at a later point.

The seat iii of the cartridge or shell l0 and the extremity 24 of the reduced portion [4 of the discharge cap l5 have confined between the same a packing ring 25 and a'hardened metallic ring 26.. This metallic ring is intended to function as which is located within the cylinder or chamber i6 of the discharge cap l6. v

The piston 29 is formed with a portion 30 which slidably fits the bore of the cylinder or chamber- I8. From the enlarged portion 30 of the piston to the conical portion 3| which blends into the rod or stem 28, the piston is provided with a reduced cylindrical portion 32. The difference in diameter between the portions 39 and 32 of the The piston 29 outwardly of its enlarged portion 30 is formed with a reduced extension 34 which is, externally screw-threaded. A cup leather 35 is held against the surface 36 of the piston portion 30 by means oi a ring or nut 31.

Threadedly connected to the extremity of the reduced piston portion 34 is a spider or guide head 39. Figure 3 discloses this spider or guide head as including the radially projecting fins 40 which are arranged in circumferentially spaced relation to provide the series of openings 4|.

The portions 30,32 and 34 of the piston 29 are bored to form a cylinder 42. The outer end of this cylinder isclosed by the spider 39. The inner end of this bore or cylinder has formed in its wall a frusto-conical pocket 43. Extending from the inner end wall of this pocket through the rod or stem'28 and the axis of the valve head 21 is a passageway 44 which establishes. communication between the interior or bore of the cartridge l0 and the bore or cylinder 42 of the piston 29..

A valve 46 is arranged to control communication between the passageway 44 and the bore 42 of the piston. Formed integrally withthe valve 46 is a plunger 46 which is slidably fitted within the bore 42 of the piston. Projecting axially from the plunger 46 is a stem 41 which is encircled by a compression spring 46. One end of the spring 46 bears against the surface of the plunger 46 while the other end of the spring bears against the inner surface oi the spider 39. This spring functions to retain the valve 46 seated to prevent flow of fluid from the passageway 44 into the bore 42 of the piston 29.

A cup leather 49 is retained against the plunger 46 by means of a retaining nut 60. The cup leather 49 functions, during axial movement or the plunger 46, as a valve for controlling flow of fluid through the bY-D8SS which extends from the bore 42 .ot the piston to and through the surface 36 of the piston portion 36. It will be noted that the central opening of the cup leather 36 is of a proper diameter to provide a chamber 62 which communicates with the by-pass 6| and is of annular formation. The nut 31 is provided with one or more axial passageways 63 which communicate with the annular chamber 62.

A port 64 is provided to vent the portion of the bore 42 of the piston 29 which is arranged bemally functions to retain the valve head 21 seated against the ring 26. The pressure of the charge within the cartridge I6 is delivered through the passageway 44 to the valve 46 which is carried by the plunger 46. Due to the relatively small area of the passageway 44, the valve 46 is subjected to 6 a comparatively small force. The spring 46 should be of proper strength to retain the valve 46 seated until the desired blasting pressure is obtained within the cartridge l6; jfor example, a

pressure'of from 10,000 to 15,000 lbs. per square 10 inch. .When such a pressure is obtained in the cartridge II, the valve 46 will be unseated. A slight opening movement of the valve 46 will permit pressure to build up within the bore-42 oi the piston 29 between the inner end of this bore 15 and the plunger 7 46. This pressure will set against the cup leather 49 and the nut 66 to force the plunger 46 axially against the pressure of the spring 46. It will be appreciated that the cup leather 49 will function to prevent leakage of the 20 blasting medium past the plunger 46. Should any of the blasting medium leak past the cup leather, the same will be vented through the port 64 to the exterior of the piston. It will be ap-. preciated, therefore, that a pressure can not build 26 up in back of plunger 46 which would result in premature closing of valve 465' 3 Axial movement of the plunger 46 with the cup leather 49 will move the latter to uncover the inner end of the by-pass 6i. The blasting 30 medium, then will'ilow from the cartridgell through the passageway '44 into the bore 46 oi;' the piston and from said bore through the by-' Pass 6| into the annular chamber 62. The blasting medium will be discharged-from the chamber 36 62 into the cylinder or chamber l6 formed in the discharge cap l6 through the ports 63. The pressure of the blasting medium will build up in the chamber or cylinder ll of the discharge cap until it susbtantially equals the pressure within 40 the chamber of the cartridge ill or until it reaches a value which, acting upon the exposed surfaces of the nut 31 and cup leather 36 and the spider 39 will. overcome the pressure within the cartridge III which is fimctioning to retain valvehead 21 5 provide atotal area whichis in excess of the area or diameter of the valve head 21. The pressure built .up within the chamber ll of the discharge 0 cap l6, therefore, will function to move the valve head 21 oil of its seat. Unseating of the valve head 21 will permit the blasting charge to be releasedjrom thetcartridge. l3 intoithe discharge It will be appreciated that the cup leather 36 will effect a seal between the piston 29 and the chamber I6 to permit pressure to be built up in the chamber. This blasting medium delivered to Q the chamber l6 normally willbe exhausted therefrom by slowly leaking past the cup leather 66'. If, however, the cup leather so tight y seals the T chamber I6 that the charge will not leak past the said cup leather, the valve 22 may be backed .5 away from its seat to reduce the pressure within the chamber to atmospheric pressure. The mechanism then'will be in readiness to receive and eil'ect release of a second charge from the cartridge chamber.

It. further will be appreciated that by varying the strength of the spring 46, the pressure at which the blasting charge will be released from the cartridge l0 may be varied.

Itistobeunderstoodthat the formofthisincap l6 and outwardlythro k thedis chargem 66 vention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size, and

arrangement of parts may be resorted to withoutpressure of which is to be built up to the desired blasting pressure, release means for the blasting charge, a control chamber, means in said control chamber for opening said release means when a portion of the blasting charge is admitted to the control chamber and for holding open said release means as long as the-blasting charge remains in the control chamber, and means carried by the control chamber means and subjected to the pressure 01. the charge in the first-mentioned chamber for establishing communication between the two chambers when the pressure of the blasting charge reaches a predetermined value and for maintaining said communication until the blastingcharge has been entirely released.

2. In combination, a blasting cartridge having a chamber for receiving a blasting charge the pressure of which is to be built up to. the desired blasting pressure, a discharge cap attached to the cartridge,'and means embodied in the discharge cap for releasing the charge from said chamber when the pressure of the charge reaches a predetermined value, said means including a charge releasing valve held closed by the pressure of the charge, a piston connected to the valve for opening-and holding open the same when subjected to the pressure of the charge, and means operated by the pressure of the charge for subjectin the piston .to the charge pressure and for maintaining said piston so subjecteduntil the pressure in the blasting charge chamber drops to atmospheric pressure.

3. In combination, a blasting cartridge having a chamber for receiving a blasting charge the pressure of which is to be built up to the desired blasting pressure, a discharge cap attached to the cartridge, and means embodied in the discharge cap for releasing the charge from said chamber when the pressure of the charge reaches a predetermined value, said means including a charge releasing valve held closed by the pressure of the charge, a piston connected to the valve for opening and holding open the same when subjected to -the pressure of the charge, and means carried by said piston and operated by the pressure of the charge for subjecting the piston to the charge pressure and for maintaining said piston so subjected until the pressure in the blasting charge chamber drops to atmospheric pressure.

4. In combination, a blasting cartridge having a chamber for receiving a blasting charge the pressure of which is to be built up to the desired blasting pressure, a discharge cap attached to the cartridge, and means embodied in the discharge cap for releasing thecharge from said chamber when the pressure of the charge reaches a predetermined value, said means including a charge releasing valve held closed by the pressureof the charge,

a'hollow piston connected to the valve for opening and holding open the'same when subjected to th e'pressure of the charge, and means-located in the bore of the piston for'causing the piston to be subjected 'tothe charge pressure and for maintaining said piston so subjected until the pressure in the blasting charge chamber drops to atmospheric pressure.

5. In combination, a blasting cartridge having a chamber for receiving a blasting charge the pressure of which is to be built up to the desired blasting pressure, a discharge cap attached to the cartridge, and means embodied in the discharge cap for releasing the charge from said chamber when thepressure' of the charge reaches a predeterlnined value, said means including a charge releasing valve held closed by the pressure of the charge, a hollow piston having a rod connected to the valve for opening and holding open the valve when the piston is subjected to the pressure of the charge, a passageway through the valve and rod connecting the charge receiving chamber and the bore of the piston, and means in the piston bore for establishing and maintaining flow of the blasting charge through said passageway until the charge is exhaustedto cause the piston to be subjected to the charge pressure, said last mentioned means comprising a valve sealing the piston bore end of the said passageway and a difierential pressure piston connected to the valve.

6. In combination, a blasting cartridge-having a chamber for receiving a blasting charge the pressure of which is to be built up to the desired blasting pressure, a discharge cap attached to the cartridge, and means embodied in the discharge cap for releasing the charge from said chamber when the pressure of the charge reaches a predetermined value, said means including a charge releasing valve held closed by the pressure of the charge, a hollow piston having a rod, connected to the valve for opening and holding open the valve when the piston is subjected to the pressure of the charge, a passageway through the valve and rod connecting the charge receiving chamber and the bore of the piston, and means in the piston bore for establishing and maintaining flow of the blasting charge through said passageway until the charge is exhausted to cause the piston to be subjected to the charge pressure, said last-mentioned means including a spring pressed valve.

7. In combination, a blasting cartridge having a chamber for receiving a blasting charge the pressure of which is to be built up to the desired blasting pressure, a discharge cap attached to the cartridge, and means embodied in the discharge cap for releasing the charge from said chamber when the pressure of the charge reaches a predetermined value, said means including a charge releasing valve held closed by the pressure of the'charge, a hollow piston having a rod connected to the valve for opening and holding open the valve when the piston is subjected to the pressure of the charge, a passageway through the valve and rod connecting the charge receiving chamber and the bore of the piston, and means in the piston bore for establishing and maintaining flow of the blasting charge through said passageway until the charge is exhausted to cause the piston to be subjected to the charge pressure, said last-mentioned means including a spring seated blasting pressure opened compound valve assembly.

8. In combination, a blasting cartridge having a chamber for receiving a blasting charge the pressure of which is to be built up to the desired blasting pressure, a discharge cap detachably connected to said cartridge, a ring forming a valve seat clamped between portions of the cartridge and the discharge cap, a valve for controlling communication between the cartridge and the discharge cap, and charge pressure operated mechanism in the discharge cap for unseatlng said valve;

9. In combination, a blasting cartridge having pressure of which is to be built up to the desired blasting pressure, a discharge cap threadedly connected to the cartridge, valve seat forming means clamped between portions of the cartridge and discharge cap, a valve enga ng said valve seat means on the cartridge side otithe latter, and charge pressure operated means in the discharge cap for moving the valve inwardly ot the cartridge to unseat the valve.

10. In combination, a blasting cartridge having a chamber for receiving a blasting charge the pressure of which is to be built up to the dedred blasting pressure, a discharge cap threadedly connected to the cartridge, a valve seat forming ring and a packing ring clamped between portions of the cartridge and said cap, a valve head.

held against said seat by the pressure ,of the charge within the cartridge, mechanism within the discharge'cap for unseating said valve head when said mechanism is subjected to the pressure of the charge within the cartridge, and meansoperated by the charge pressure for controlling application of said charge pressure to said mechanism.

11. In combination, a blasting cartridge having a chamber for receiving a blasting charge and provided with a discharge orifice. and differential release mechanism operated by the blasting charge when the pressure 01 the same reaches a predetermined value for discharging the blasting charge, said mechanism comprising a discharge orifice control valve normally subjected to the pressure or the blasting charge, a piston of greater transverse area than said valve operatively connected to the latter and normally subjected to atmospheric pressure when said chamber is charged, means operated by the blasting charge when the pressure of the same reaches the desired value for causing the piston to be subjected to and moved by the pressure oi the charge to eil'ect opening of said-valve, and means to atmospheric pressure when said chamber is charged, a flow path for conducting a portion oi! the blasting charge irom said chamber to one side of said piston, a spring loaded valve for controlling said ilow path adapted to be imseated by the blasting charge when the pressure of the same reaches the desired value, and means for eii'ecting and maintaining full opming of the spring loaded valve.

13. In combination, a blasting cartridge havirg a chamber for receiving a blasting chargeand provided with a. discharge orifice, and diilerential release mechanism operated by the blasting charge when the pressure 01' the same reaches a predetermined value for discharging the blasting charge, said mechanism comprising a discharge orifice control valve normally subjected to the pressure of the blasting charge, a piston of greater transverse area than said valve operatively connected to the latter and normally subjected to a chamber for receiving a blasting charge the atmospheric pressure when said chamber is charged, a flow path for conducting a portionot the blasting charge from said chamber to one side of said piston, a spring loaded valve for controlling said flow path adapted to be unseated by the blasting charge-when the pressure at the same reaches the desired value, and means operated by the pressure ot the charge flowing past said unseated valve tor electing and maintaining full opening of the latter.

14. In combination, a blasting cartridge had a chamber for receiving a blasting charge and provided with a discharge orifice, and diilerential release mechanism operated by the blasting charge when the pressure or the same reaches a predetermined value for discharging the blasting charge, said mechanism comprising a discharge orifice control valve normally subjected to the pressure of the blasting charge, a piston or greater transverse area than said valve operativelyconnected to the latter and normally subjected to atmospheric pressure when said chamber is charged, a ilow path for conducting a portion or the blasting charge from said chamber to one side of said piston, a spring loaded valve ior controlling said flow path adapted to be umeated by the blasting charge when the pressure or. the same reaches the desired value, and a plunger subjected to the pressure or the charge flowing past the unseated valve for eilecting and maintaining fullopening of the latter.

15. In combinatloma blasting cartridge having a chamber for receiving a blasting,charge the pressure of which is to be built up to the desired blasting pressure, release means for the blasting charge, a control chamber, means in said control chamber for opening said release means when a portion of the blasting charge is admitted to the control chamber, means carried by thecontrol chamber means and subjected to the pressure or the charge inthe first-mentioned chamber for admitting the blasting charge to the control chamber when the pressure of the blasting chargereaches a predetermined value, and means for maintaining the control chamber subjected to the pressure of the blasting charge until the entire charge is released.

16. In combination, a blasting cartridge having a chamber for receiving ablasting charge the pressure oi. which is to be built up to the desired blasting pressure, a discharge cap 'attached to the cartridge, and means embodied in the discharge cap for releasing the charge from said chamber when the pressure of the charge reaches a predetermined value. said means including a charge release valve held closed by the pressure of the charge, a piston connected to the valve for opening the same when subjected to the pressure of the charge. means operated by the pressure of the charge for subjecting the piston to the charge pressure, and means for maintaining the piston subjected to the charge pressure until the entire charge is released.

4 17. In combination, a blasting cartridge having a chamber for receiving a blasting charge the prwsureof which is to be built up to the desired blasting pressure, a discharge cap attached to the cartridge, and meanstembodied in the discharge cap for releasing the charge from said chamber'when the pressure of the charge reaches a predetermined value. said means including a. charge release valve held closed by the pressure of the charge, a piston connected to the valve for opening the same when subjected to the pressure of the charge, means carried by said piston and operated by the pressure of the charge for subjecting the piston to the charge pressure, and means for maintaining the piston subjected to the charge pressure until the entire charge is released.

18. In combinatiom a blasting cartridge having a chamber forreceiving a blasting charge the pressure of which. is to be built up to the desired blasting pressure, a discharge cap attached to the cartridge, and means embodied in the discharge cap for releasing the charge from said chamber when the pressure of the charge reaches a predetermined value, said means including a charge releasing valve held closed by the pressure of the charge, a hollow piston connected to the valve for opening the same when subjected to the pressure of the charge, means located in the bore of the piston for causing the piston to be subjected to the charge pressure, and means for maintaining the piston subjected to the charge pressure until the entire blasting charge is released.

19. In combination, a blasting cartridge having a chamber for receiving a blasting charge the pressure of which is to be built up to the desired blasting pressure, a discharge cap attached to the cartridge, and means embodied in the discharge cap for releasing the charge from said chamber when the pressure of the charge reaches a predetermined value, said means including a charge releasing valve held closed by the pressure of the charge, a hollow piston having a rod connected to the valve for opening the valve when the piston is subjected to the pressure of the charge, a passageway through the valve and rod connecting the charge receiving chamber and the bore of the piston, and means in the piston bore for controlling the flow of the blasting charge through said passageway to cause the piston to be subjected to the charge pressure and to be maintained subjected to said charge pressure until the entire blasting charge is released. i

20. In combination, a blasting cartridge having a chamber for receiving a blasting charge the pressure of which is to be built up to the desired blasting pressure, a discharge cap attached to the cartridge, and means embodied in the discharge cap for releasing the charge from said chamber when the pressure of the charge reaches a predetermined value, said means including a charge release valve held closed by the pressure of the charge, a hollow piston having a rod connected to the valve for opening the latter when the piston is subjected to the pressure of the charge, a passageway through the valve and rod connecting the charge receiving chamber and the bore of the piston, means in the piston bore for controlling flow of the blasting charge through said passageway to cause the piston to be subjected to the charge pressure,

said last-mentioned means including a spring pressed valve, and means for holding said spring pressed valve open until the entire blasting charge is released.

21. In combination, a blasting cartridge having a chamberfor receiving a blasting charge the pressure of which is to be built up to the desired blasting pressure, a discharge cap attached to the cartridge, and means embodied in the discharge cap for releasing the charge from said chamber when the pressure of the charge reaches a predetermined value, said means including a charge releasing valve held closed by the pressure of the charge, a hollow piston having a rod connected to the valve for opening the latter when the piston is subjected to the pressure of the charge, a passageway through the valve and rod connecting the charge receiving chamber and the bore of the piston, means in the piston bore for controlling flow 0f the blasting charge through said passageway to cause the piston to be subjected to the charge pressure, said lastmentioned means including a blasting pressure operated compound valve assembly, and means for holding said valve assemblies open until the entire blasting charge is released.

22. In combination, a blasting cartridge having a chamber for receiving a blasting charge and provided with a discharge orifice, and differential release mechanism operated by the blasting charge when the pressure of the same reaches a predetermined value for discharging the blasting charge, said mechanism comprising a discharge orifice control valve normally subjected to the pressure of the blasting charge, a piston of greater transverse area than said valve operatively connected to the latter and norma ly subjected to atmospheric pressure when said chamber is charged, means operated by the blasting charge when the pressure of the same reaches the desired value for causing the piston to be subjected to and moved by the' pressure of the charge to effect opening of said valve, and means for maintaining the piston subjected to the charge pressure until the entire blasting charge is released.

23. In combination, a blasting cartridge having a chamber for receiving a blasting charge the pressure of which is to be built up to the desired blasting pressure, release means for the blasting charge, a control chamber, means in said control chamber for opening said release means when a portion of the blasting charge is admitted to the control chamber, and means carried by the control chamber means and subjected to the pressure of the charge in the firstmentioned chamber for admitting the blasting charge to the control chamber when the pressure of the blasting charge reaches a predetermined value and for maintaining said control chamber subjected to the blasting charge pressure until the pressure in the first-mentioned chamber drops to atmospheric pressure.

24. In combination, a blasting cartridge having a chamber for receiving a blasting charge the pressure of which is to be built up to the desiredblasting pressure, a discharge cap attached to the cartridge, and means embodied in the discharge cap for releasing the charge from said chamber when the pressure of the charge reaches a predetermined value, said means including a charge releasing valve held closed by the pressure of the charge, a hollow piston hav-' ing a rod connected to the valve for opening the latter when the piston is subjected to the pressure of the charge, a passageway to the valve .and rod connecting the charge receiving chamber and the bore of the piston, and means in the piston bore for controlling flow of the blasting charge through said passageway to cause the piston to be subjected to the charge pressure, said last-mentioned means including a needle valve and a plunger valve successively subjected to the charge pressure.

FRANK H. ARMSTRONG. 

